1. Field of the Invention
The present invention relates to the technological field of displays, and more particularly, to a quantum dot (QD) backlight module and a display device.
2. Description of the Prior Art
Semiconductor QD fluorescent powder is a new kind of light white light emitting diode (LED) luminescent material. The semiconductor QD fluorescent powder is a kind of particle larger than H2O but smaller than viruses. The light emitted by a standard blue LED is transformed to different kinds of light with different wavelengths according to the size of the semiconductor QD fluorescent powder. A long wavelength (such as red light) emits according to a bigger semiconductor QD fluorescent powder. A short wavelength (such as green light) is transformed according to a smaller semiconductor QD fluorescent powder. The mixed particles of various sizes form a new spectrum. Owing to the feature of the QD, a quantum dot enhanced film (QDEF) is produced. The light source of the standard blue LED is used to realize the high quality white light with the three primary colors. The display quality of liquid crystal displays (LCDs) reaches to a new, high level. Compared with the conventional white LED fluorescent luminescent material, the QD fluorescent powder features broad absorption and narrow emission, higher luminous efficacy, longer service life, better color rendering properties, and purer color. So any device using the QD fluorescent luminescent material has wider color gamut and better display quality.
In the conventional technology, the QDEF is usually used in the backlight module. As FIG. 1 shows, the backlight module comprises a blue LED 10, a reflector 20, a light guide plate (LGP) 30 disposed above the reflector 20, a QD thin film 40 disposed above the LGP 30, and an optical film 50 disposed above the QD thin film 40. The blue LED 10 is disposed at the left side of the LGP 30. The QD thin film 40 transforms the blue light emitted by the blue LED 10 into red light and green light. Based on principles of energy conversion, a new, high level is transformed into a low level when no external energy intervenes. That's why the blue light emitted by the blue LED 10 is transformed into red light and green light. The three primary colors are shown on the display device. If the QD thin film 40 is disposed in the blue LED 10, heat radiation may be a problem for the light source of the blue LED 10. To solve this problem, the QD thin film 40 is presently disposed above the LGP 30. The problem of heat radiation is really settled. The wavelength of the blue light is also successfully transformed to the wavelength of the red light and the wavelength of the green light. However, the QD thin film 40 needs to be as big as the LCD panel. It is probably very hard to fully utilize the QD material. Moreover, the QD material is mostly the material with cadmium (Cd), which implies that the QD material is mostly poisoning. The packaging of the whole thin film in the process of production is a big problem because unsuccessful packaging results in dangerous and harmful Cd pollution. In addition, the QD material may become ineffective due to the influence of oxygen and water in the air.
Therefore, it is necessary to propose a new technical plan for solving the above-mentioned problem.